| Impact of NaCl treatment on content of photosynthetic pigment,intensity of photosynthesis(Pn) and chlorophyll fluorescence parameters of tomato(cv.Zhongza No.9) seedling at 6-leaf stage were studied under hydroponic culture with 0,50,100,200 or 400 mg/L of NaCl added,respectively.The results showed that the content of photosynthetic pigment was increased in the duration of salt treatment.Gs was decreased with the increase of salt concentration.After 5-day salt treatment,although the higher salt treatment was found with lower Tr value and Tr value of all treatments was found lower than the control,they all tended to little difference.At the beginning(1 day) of salt treatment,Pn of all the treatments was lower than the control,and appeared lower with higher salt concentration.Pn was getting resuming after 3-day salt treatment and maintained a relative stable level until got dropping after 11-or 13-day treatment.The similar change trends were found between Fv/Fm and Fv/Fo, and between Fo and Fm during salt treatment,and each index among all the treatments was tend to close after 9-day salt treatment. qN appeared a decreasing trend and increased with the increase of salinity concentration. |